The present invention relates to printed circuit boards and, more specifically, to techniques for mounting power handling components on printed circuit boards in regions corresponding to high density routing channels.
Electronic assemblies constructed on printed circuit boards (PCBs) often employ point-of-use regulators in close proximity to the components to which they provide power for the purpose of reducing noise and power losses. For example, each processor on a computer system motherboard might have its own associated voltage regulator module (VRM).
Recent generations of processor designs have integrated the memory controllers which facilitate communication between the processors and associated memory. As a result, high density interconnects are provided directly between the processors and the memory. Because of the extremely high operational speeds of these processor designs, the dimensions of the conductors in such high density interconnects must be carefully controlled to mitigate undesirable transmission line effects and signal skew. This difficult design constraint is made more challenging by the introduction of through-holes and vias for components mounted on the PCB in the region of the routing channels in which the interconnects are disposed.
One solution is to eliminate components on the surface of PCBs corresponding to such routing channels. However, this wastes a considerable amount of otherwise usable PCB surface area. In addition, such an approach undesirably restricts the options for placing point-of-use regulators close to the components with which high density interconnects are associated.
Another approach is to provide an interposer structure between the surface of the PCB and the circuit to which power is to be provided to which the regulator may then be connected. The disadvantage of such an approach is that it may raise the height profile of the assembly beyond acceptable limits.
It is therefore desirable to provide alternative techniques by which power handling components (such as point-of-use regulators) may be mounted on PCBs in the vicinity of high density routing channels.